Aspectos relevantes

Figure 4.3: Fastship Atlantic loading system.

A number of innovations have been proposed for external RO/RO ramps, primarily to allow them to rapidly interface with the ports, adjust for tides and any relative motion between the ship and the dock.

Figure 4.4: VibTech floating Ro/Ro ramps.

VibTech has proposed floating ramps that provide all weather RO/RO capability for almost any situation.

4.2 LO/LO Concepts

Systems such as the DARTS spreader, the intelligent spreader bar and the cell elevator are methods to improve the speed of load on / load off (LO/LO) vessels, high speed or otherwise. A commonly proposed solution for rapid loading and unloading of vessels is the design of a berth such that cranes can work both sides of the ship. Some existing, though not commonly used, commercial cranes may prove of particular value for HSS. Though not new designs, these concepts include the split trolley, dual hoist, Matson “mousetrap”, Matson bridge crane, and the O&K double jointed deck cranes.

The split trolley gantry crane separates the operator’s cab from the hoist trolley. Both units can trolley over the deck and the dock, but under different controls and at different rates. In this way the hoist trolley can be designed for maximum acceleration and velocity without concern for the comfort of the crane operator.

Dual hoist cranes have two hoisting mechanisms, one for shipside and one for landside. A common area between the two hoist mechanisms is used to transfer cargo from one to the other. While one hoist is working the dock, placing a container on a chassis for example, the other hoist is working the ship, such as picking up a container from a ship cell. While two operators are required, time saving parallel operations are performed. In addition the crane operation becomes less dependent on the timing of the yard operation in that, given space to buffer one or more containers, the shipside crane does not have to wait for a chassis before performing more ship operations.

The Matson mousetrap and bridge crane together provide an extreme example of the dual hoist crane. The mousetrap is a platform that moves with the port’s gantry crane to provide a container buffering system that can accumulate several containers (e.g. 5) in a horizontal plane. The crane operator is able to pick up or place from any of the mousetrap’s container locations. In this way the crane operator working the ship can select from one or more containers in order to keep to the stow plan. In addition system lends itself to loading and unloading the ship at the same time.

The Matson bridge crane is a very large gantry crane similar in general concept to a commonly used Transtainer, but with a coverage of over 300 feet, the crane is able to straddle many more stacks of containers. The bridge crane is able to straddle, perpendicular to the ship, many container stacks in the yard. It is also able to gantry parallel to the ship in order to cover many more container stacks. The hoisting mechanism is able to trolley the length of the bridge crane in order to access any of the stacks of containers below. When the bridge crane is positioned over the mousetrap the trolley and hoist is able to deliver or pick up container to / from the mousetrap. The system was designed, built and proven in the 1980’s. Updates of the design using the latest technology has to offer would likely result in an effective means to rapidly load and unload vessels.

O&K double jointed crane

Figure 4.5: O&K double jointed crane.

O&K double jointed cranes, employed on several vessels and ports, are similar to August Design’s Robotic Crane concept (section 2.1.3). Both cranes have articulated horizontal arms able to rotate about the shoulder and elbow joints. This allows them to access very large areas rapidly and with little movement enabling high throughput rates. The August Design Robotic Crane has the additional feature of using a rigid hoist instead of cables.

Figure 4.6: Automated all-weather cargo transfer system.

In addition to advances in crane systems for LO/LO operation, several concepts have been proposed for using overhead rail systems for loading and unloading ships. Sea-Land’s GRAIL system is an example, as well as a system proposed by MIT in the late 1980’s. The latest version of this theme is the SpeedPort. In SpeedPort container straddle carrier-like devices, called Spiders, bring cargo alongside the ship and move over the deck of the ship. The spiders along with their cargo attach themselves to overhead rails. And move over the deck of the ship. In the concept, the hoisting mechanism in the spiders is able to pick up and place cargo from the ship. Once the spiders reach the

KSW’s Automated

other side of the ship, they lower themselves to the ground where they are able to travel to the yard to pick up the next container.

Figure 4.7: SpeadPort overhead view.

Another interesting concept for rapid cargo handling has been proposed by KSW. KSW, a joint venture of Kaefer, Sabroe, and Westfalia, has developed the Automatic Seaborne Pallet Handling (ASPH) system. The ASPH was specifically designed for refrigerated cargo that is often the cargo of economic choice in high speed transport. ASPH consists of a ship that combines containers and a below deck automated pallet storage system. While the physical infrastructure required in the ship may limit its potential in a HSS, a version of the concept may prove useful.

Figure 4.8: KSW’s Automated Seaborne Pallet.

SpeedPort overhead view